Method and apparatus for monitoring capacitance of DC bus capacitor

摘要

A method for monitoring capacitance of DC bus capacitor of a power electronic converter is provided, wherein the power electronic converter includes at least one AC/DC conversion circuit and the DC bus capacitor, a power input/output interface of the AC/DC conversion circuit including a first terminal and a second terminal. The first terminal is connected to an AC grid with a frequency of f, the second terminal is connected to the DC bus capacitor, f is any positive real number, and the method includes: measuring a pulsating power with a frequency of 2f flowing through the DC bus capacitor and a voltage on the DC bus capacitor; and calculating the capacitance of the DC bus capacitor based on the pulsating power and the voltage on the DC bus capacitor. An apparatus for monitoring the capacitance of the DC bus capacitor is provided correspondingly.